Hello everyone. I am building a class T amp for a class project. My instructor has a demo that he built using mostly surface mount resistors and caps. It sounds pretty good, but I am wondering if high quality through-hole components will give me better sound quality? I'm aiming to squeeze all of the fidelity I can out of this little chip.

There is a common misconception that through hole parts "sound" better than surface mount parts. There are differences in construction methods and quality between any kind of parts. You can get a good metal film resistor in a surface mount or through hole package that for all audio intents and purposes will perform equally.

The advantage of surface mount components is that they give you more flexibility when routing a PCB. Smaller parts can mean a tighter layout, less parasitics, and better performance at higher frequencies (i.e. class d).

Smaller components tend to produce better performance in my experience. One of the larger issues the designer has to deal with is HF EMI induced into the small signal linear stage (front end buffers, etc). Keeping the parts tiny helps to keep loops small and keeps potential antennas small.

The same argument can be made for the power / driver stages; smaller parts keep radiating loops and parasitic inductances small.

All of this within the constraints of appropriate power dissipation and voltage ratings of course.

A notable exception are the resistors used for feedback. Even Rs have voltage coefficients and SMT Rs have worse performance in this regard. 0402s worse than 0603, etc. Stick with 1206 or 2x1206 to be safe.

Originally posted by Boomy Hello everyone. I am building a class T amp for a class project. My instructor has a demo that he built using mostly surface mount resistors and caps. It sounds pretty good, but I am wondering if high quality through-hole components will give me better sound quality? I'm aiming to squeeze all of the fidelity I can out of this little chip.

in class-d, yes,
u can get low Distribution of capacitance and inductance ,
it make ur damp running fine in a hi-speed.

but some high power project, u cant find or hard to find a hi-power Component in SMD,